Originally Posted by Markeologist

The model of Mafacs on the Geminiani in link are Mafac Tigers which predate Top 63s by three years if I recall. The Tigers have a much flatter face on arm and a much broader and flatter arc to the arms than Top 63s. The flatter, broader arc to arms wasn't seen on subsequent Mafac models (perhaps a poor design and why they were replaced by Top 63s so quickly). The Top 63s were replaced pretty quickly too (from what I understand they are pretty complicated to set up) by the original Racers which were not embossed with "Racer" just "Mafac" and "Dural Forge" (the aluminum alloy they were made of). Racers seem to my eye to be a bland of Tigers and Top 63s and were the choice of many professional riders in the latter half of the 60s. The later Racers actually embossed with name "Racer" are 70s versions and used plastic bushings instead of the bronze bushings found earlier.